Pulp strainer and clearer



(NovModel.)

C. J. FOSTER. PULP STRAINER AND GLEARBR.

Y hmmno.

a l I' U NiTED STATES PATENT OFFICE.

CHARLES J. FOSTER, OF VVESTBROOK, MAINE.

PULP STRINER AND CLEARER.

SPECIFICATION forming part of Letters Patent No. 436,345, datedSeptember 16,1890.

Application led November 4,1889. Serial No. 329.187. (No model.)

To ZZZ whom it may concern.'

Be it known that I, CHARLES J. FOSTER, of Westbrook, in the county ofCumberland and State of Maine, have invented certain new and usefulImprovements in Pulp Strainers and Clearers; and I do hereby declarethat the fol lowing is afull, clear, and exact description of theinvention, which will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to lett-ers of reference marked thereon,which form a part of this specification.

My invention relates to improvements in pulp-screening machines. Itconsists of a stationary vat having a screen in the bottom thereof, adiaphragm connected to said vat by a suitable packing and having a valvetherein, and means for imparting a vibratory motion to said diaphragmand to open and shut said valve at stated times with reference to theposition of said diaphragm, in such manner that the upward or clearingforce of the machine shall be greater than the downward or strainingforce.

In the drawings herewith accompanying and making a part of thisspecification, Figure lis a central Vertical section of my improvedmachine; Fig. 2, an end elevation; and Fig. 3 is a detail showing camsand connecting-rods for the diaphragm and valve and the position of thecams on the shaft relative to each other, the cam and connecting-rodthat operates the diaphragm being shown in dotted lines, and sameletters refer to like parts.

In said drawings, d shows a hopper or vat into which the pulp is placedbefore strainn ing, and b the strainer-plate in the bottom thereof, saidvat being supported by a suitable frame c.

Beneath the vat is a diaphragm CZ, arranged so as to form a more or lessnearly air-tight connection between it and said vat and to have avibratory movement in a vertical direction.

The upper sides of the diaphragm d may extend up between the outside ofthe vat and the inside of the supporting -framev This serves to steadythe diaphragm.

Between the diaphragm CZ and the vat a is a packing e to make a tightconnection, that shown in the drawings being a cylindrical rubber, whichwill roll up and down as the diaphragm vibrates. Instead of the rubbershown, a leather or other iieXible substance may be stretched from theoutside of the vat to the diaphragm to form the packing.

The diaphragm receives a vibratory motion from cams f, arranged upon theshaft g so as to strike against the connecting-rods h, rigidly attachedto the diaphragm. These cams f have the shape substantially as shown inthe dotted lines in Fig. 3, having the part S, in which the diametergradually decreases, and the part t,in which itsuddenly increases, so asto give the diaphragm a very sudden upward motion, to hold it at itshighest ele vation for half, more or less7 of the revolution of the camsandthen permit it to drop slowly.

The bottom of the diaphragm may slopev toward a common center, and hasin said bottom a valve t', adapted to open and shut by means of a cam j,having a segment u, which engages the connecting-rod a part of the timeonly, set on shaft g, and a connecting-rod Zt, attached to a lever Z,one end of which is pivoted at m to the diaphragm and the other adaptedto carry the valve t'.

The operation of the valve 7l with reference to the movement of thediaphragm may be seen by the arrangement of the cams f andj with respectto each other on the shaft g, as shown inFig. 3.

n and o are fast and loose pulleys, respectively, for operating themachine, and p is a stay to steady the lever which carries the valve,and q and r are stays to support the connecting-rods h and k,respectively.

The operation of my improved machine is as follows: The ground pulp isintroduced into the vat and the diaphragm iilled with water, the valvet' being closed, as shown in the drawings. The shaft g, with its cams,is then revolved, the part t, striking the connecting-rods, forces thediaphragm upward with a sudden movement, and the diaphragm being fulland the valve closed a part of the contents ofthe diaphragm is forced upthrough the holes in the strainer-plate, thus keeping said holes frombeing stopped up by the pulp or any foreign substance. .As soon as thediaphragm is raised as far as cams f will carry it, the cam 7' strikesthe connecting-rod IOO k, which operates the, valve-lever and opens thevalve, allowing a portion of the contents of the diaphragm to escapetherethrough. As the contents of the diaphragm escape through the valve,an equal quantity of the pulp in the Vat passes down through the holesin the strainer-plate. As the shaft g continues its revolution, the camf at length ceases to hold up the valve and it returns to its seat, andthereafter the cams f permit the diaphragm. to fall graduallypreparatory to being again forced up to clear the strainer-plate, and soon continually. It will thus be seen that. the upward force is suddenand violent to effectually clear the screen, while the downward force isgrad ual and easy to draw or suck the pulp through the strainer.

The advantages of my improved machine consist in the fact thatitdoes notget clogged, it does not suck through the screen any coarse matter, ithas a greater clearing force than straining force, the packing is all onthe outside where it can be easily looked after to prevent wear, thepulp is strained more evenly, and the machine is cheaper than others, inthat it does more work in a given time.

I-Iavng thus described my invention and its use, what I claim, anddesire to secure by Letters Patent of the United States, is-

1. The combination,in a pulp-screening machine, with a stationary vathaving a screen in the bottom thereof,l of a vibratory diaphragm, asuitable packing between said vat and diaphragm, a valve in saiddiaphragm, and mechanism, substantially as set forth, for imparting avibratory motion to the diaphragm and t0 open and close the valve, asand for the purposes set forth.

2. In a pulp-screening machine, the combination, with a stationary vathaving a screen in the bottom thereof, of a diaphragm connected to saidvat by a suitable packing and having an escape-Valve therein, and meansfor imparting a vibratory motion to said diaphragm and to open and shutsaid Valve atstated times with reference to the position of saiddiaphragm, for the purposes set forth.

3. In a pulp-screening machine, the combination, with a stationary Vathaving a screen in the bottom thereof, of a vibratory diaphragm, asuitable packing between said diaphragm and vat, and escape-valve insaid diaphragm, and mechanism, substantially as set forth, adapted toimpart to said diaphragm a vibratory motion of varying velocity and toopen and shut said valve at stated times with reference to the positionof the diaphragm, as and for the purposes set forth.

In testimony that I claim the foregoing as my own I affix my signature,in presence of two witnesses, this 24th day of October, A. D. 1889.

' CHARLES J. FOSTER.

Vitnesses:

ELGIN C. VERRILL,

WILLIAM HENRY CLIFFORD.

